Now the 'silver fox' who worked as a journalist for NBC-26, and has garnered quite an appreciative following on social media, has revealed he still has questions about the case.

He told Rolling Stone that he has questions about the evidence which led to Avery's conviction for Halbach's murder, and also regarding the close relationship between other news outlets and the police.

Keller, who has not seen all of the Netflix series, questions whether or not there was a bad thunderstorm within the first couple of days when Teresa was reported missing and whether or not this may have removed Avery's fingerprints from her vehicle had they been present.

"Because if there was a deluge, would it have wiped away some potential evidence? But it might have been when they were searching like a year later, because there were a couple of searches in there," he told Rolling Stone.

The magazine reports that there was indeed a thunderstorm in Manitowoc two days after Teresa was reported missing, and another on the day after Avery was arrested.

Steven Avery is shown in a booking photo from the Netflix documentary series 'Making a Murderer'. Photo: Reuters

Keller also questions where rival news outlet WBAY-TV got the story that Steven Avery was the last person to have seen Teresa alive.

"Because it raises the question of whether Steven Avery called them and told them he was the last one to see her, or did law enforcement call them and tell them that he was the last one who had seen her?" he said.

He added, "It paints a picture, potentially of the media environment in Green Bay at the time" and went on to say that WBAY-TV "are pretty tight with the law-enforcement community."

Keller no longer works as a journalist. Inspired by Avery's defence lawyers Dean Strang and Jerry Buting, he went on to study law and become a university professor.